Planographic printing method, original printing plate and printing press

Abstract

In a planographic printing method, an as-per-image distribution of hydrophilic are as and hydrophobic areas is formed by heating the surface of an original plate to a temperature ranging from 40 through 200° C. and irradiation of activation light after uniformly making the layer of a hydrophobic substance on an original printing plate having photo catalyst power. The hydrophobic areas receive ink whereby printing is carried out. An original printing plate having photo catalyst thin film therefor and a printing press therefor are also provided.

1 . A planographic printing method, comprising the steps of: 
 uniformly providing a layer of a hydrophobic substance on an original printing plate having photo catalyst power;    forming a distribution of a hydrophilic area and a hydrophobic area as per image by heating the surface of said original plate to a temperature ranging from 40 through 200° C. and irradiating activation light thereonto; and    performing printing by said hydrophobic areas accepting printing ink.    
     
     
         2 . The planographic printing method according to  claim 1 , wherein at least irradiating by said activation light is carried out as per image.  
     
     
         3 . The planographic printing method according to  claim 1 , wherein at least heating to said temperature ranging from 40 through 200° C. is carried out as per image.  
     
     
         4 . The planographic printing method according to  claim 1 , wherein heating of said original plate to said temperature ranging from 40 through 200° C. is carried out by light irradiation simultaneously with irradiating said activation light, and said activation light is irradiated so that the area thereof is included in an irradiation area for heating.  
     
     
         5 . The planographic printing method according to  claim 3 , wherein heating of said original plate to said temperature ranging from 40 through 200° C. is carried out by light irradiation simultaneously with the irradiation of said activation light, and a heating light is irradiated so that the area thereof is included in an irradiation area of said activation light.  
     
     
         6 . The planographic printing method according to  claim 1 , wherein the method for providing the layer of said hydrophobic substance is selected from the group consisting of a coating process, a spraying process, a vaporizing condensation process, a gas contact process, and an immersing and coating process.  
     
     
         7 . The planographic printing method according to  claim 1 , wherein said hydrophobic substance is one of a sublimating solid and a volatile liquid, and a gas of said hydrophobic substance is condensed on the surface of said original orintung plate to provide the layer of said hydrophobic substance.  
     
     
         8 . The planographic printing method according to  claim 1 , wherein said hydrophobic substance is a macromolecular organic compound, and one of a solution and granular dispersoid of said macromolecular organic compound is sprayed onto the surface of said original printing plate to provide the layer of a hydrophobic substance.  
     
     
         9 . The planographic printing method according to  claim 1 , wherein ink is removed from a printing plate once used for printing, and said printing plate is reused as an original printing plate.  
     
     
         10 . An original plate for planographic printing having photo catalyst power and used for printing by a planographic printing method, comprising the steps of: 
 uniformly providing a layer of a hydrophobic substance on an original printing plate having photo catalyst power;    forming distributions of hydrophilic and hydrophobic areas as per image by heating the surface of said original plate to a temperature ranging from 40 through 200° C. and irradiating activation light thereonto; and    performing printing by said hydrophobic areas accepting printing ink.    
     
     
         11 . The original plate for planographic printing according to  claim 10 , wherein the surface of said original plate for planographic printing, as a substance having photocatalyst power, comprising: 
 a metal oxide selected from the group consisting of TiO 2 , RTiO 3  (R is an alkaline earth metal atom), AB 2-X C X  D 3-X E X O 10  (A is a hydrogen atom or alkaline-metal atom, B is an alkaline earth metal atom or lead atom, C is a rare-earth atom, D is a metal atom belonging to the group 5A elements of the periodic table, E is a metal atom belonging to the group 4A elements, and X indicates an optional figure from 0 through 2), SnO 2 , ZrO 2 , Bi 2 O 3 , ZnO and iron oxides expressed in terms of FeO x  (x=1 through 1.5).    
     
     
         12 . The original plate for planographic printing according to  claim 10 , wherein a heat insulating layer is provided between a layer having photo catalyst power and a substrate.